1. Field of the Invention
This invention generally relates to an input pen and input device.
2. Description of the Related Art
A conventional pen-type coordinate input device does not include a function of detecting a pen pressure on a transmitter, in the case where the conventional input device employs another method rather than a tablet method, which utilizes electromagnetic waves, for example, an ultrasonic method. Therefore, the transmitter was able to transmit only two types of information to a receiver, writing or not writing.
Accordingly, it was impossible to change a line width in drawing depending on the pen pressure sensed by the transmitter, with an application software on a host machine that is connected to the receiver. There is the drawback in that a drawing is expressed with a given line width only. The techniques have been proposed by Japanese Patent Application No. 7-261906 (hereinafter referred to as Document 1) and Japanese Patent Application No. 5-87633 (hereinafter referred to as Document 2) so as to solve the above-mentioned drawback.
Document 1 discloses a device that intermittently outputs several different patterns of electric waves from a pen tip, according to an output signal of a pressure sensor to which the pen pressure of the pen tip is applied. The position of the pen tip and the intermittent pattern that is formed by detecting the electric waves are decrypted with the signals detected by a pen position detecting sensor in order to determine the line width to be displayed on a flat panel. It is thus possible to draw lines and characters having various expressions in the same manner as drawing the lines and characters on a paper with a calligraphy-brush.
Document 2 discloses a device including a magnetism-generating element and a hall element so that an output from the hall element is applied to the tablet as pen pressure information. The output from the hall element varies corresponding to the changes in an up-and-down movement of a pressing member.
The device in Document 1 detects the pen pressure of the pen tip with the pressure sensor; however, it is also possible to detect the pen pressure of the pen tip with another method. The device in Document 2 detects the pen pressure of the pen tip with the magnetism generating element and the hall element; however, it is also possible to detect the pen pressure of the pen tip with another method.